EP0383254A2 - Lift-truck with a vertically spring-preloaded drive unit - Google Patents

Lift-truck with a vertically spring-preloaded drive unit Download PDF

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Publication number
EP0383254A2
EP0383254A2 EP90102780A EP90102780A EP0383254A2 EP 0383254 A2 EP0383254 A2 EP 0383254A2 EP 90102780 A EP90102780 A EP 90102780A EP 90102780 A EP90102780 A EP 90102780A EP 0383254 A2 EP0383254 A2 EP 0383254A2
Authority
EP
European Patent Office
Prior art keywords
lifting
lever
pallet truck
drive unit
lifting cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP90102780A
Other languages
German (de)
French (fr)
Other versions
EP0383254B1 (en
EP0383254A3 (en
Inventor
Eugen Prinz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Wagner Foerdertechnik GmbH and Co KG
Original Assignee
Wagner Foerdertechnik GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wagner Foerdertechnik GmbH and Co KG filed Critical Wagner Foerdertechnik GmbH and Co KG
Priority to AT90102780T priority Critical patent/ATE95127T1/en
Publication of EP0383254A2 publication Critical patent/EP0383254A2/en
Publication of EP0383254A3 publication Critical patent/EP0383254A3/en
Application granted granted Critical
Publication of EP0383254B1 publication Critical patent/EP0383254B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
    • B62B3/00—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor
    • B62B3/04—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment
    • B62B3/06—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground
    • B62B3/0612—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground power operated
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/07559—Stabilizing means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/07572—Propulsion arrangements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
    • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
    • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
    • B66F9/075—Constructional features or details
    • B66F9/07586—Suspension or mounting of wheels on chassis
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00—Arrangements for image or video recognition or understanding
    • G06V10/70—Arrangements for image or video recognition or understanding using pattern recognition or machine learning
    • G06V10/764—Arrangements for image or video recognition or understanding using pattern recognition or machine learning using classification, e.g. of video objects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2300/00—Indexing codes relating to the type of vehicle
    • B60G2300/02—Trucks; Load vehicles
    • B60G2300/022—Fork lift trucks, Clark
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
    • B62B2301/00—Wheel arrangements; Steering; Stability; Wheel suspension
    • B62B2301/08—Wheel arrangements; Steering; Stability; Wheel suspension comprising additional wheels to increase stability
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
    • B62B2301/00—Wheel arrangements; Steering; Stability; Wheel suspension
    • B62B2301/20—Resilient wheel suspension using springs
    • B62B2301/23—Resilient wheel suspension using springs the pressure of the wheel on the ground being controlled, e.g. by the load or the wheel slip
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62B—HAND-PROPELLED VEHICLES, e.g. HAND CARTS OR PERAMBULATORS; SLEDGES
    • B62B3/00—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor
    • B62B3/04—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment
    • B62B3/06—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground
    • B62B3/0625—Hand carts having more than one axis carrying transport wheels; Steering devices therefor; Equipment therefor involving means for grappling or securing in place objects to be carried; Loading or unloading equipment for simply clearing the load from the ground using rigid mechanical lifting mechanisms, e.g. levers, cams or gears

Definitions

  • the invention relates to a pallet truck, preferably a drawbar-controlled pedestrian pallet truck, with a drive unit that is spring-loaded in the vertical direction, which is articulated in a height-adjustable manner by means of a lever parallelogram suspension on a frame part of the pallet truck that cannot be raised and whose ground contact pressure can be varied depending on the load force and with a lifting cylinder for the low lift (base stroke ) of liftable frame parts.
  • the invention has for its object to provide a simple functioning and therefore reliable device in a pallet truck of the generic type with a minimum of effort and manufacturing costs, with which on the one hand minimizes the steering force required for the drawbar connected to the drive during operation and on the other hand the the braking or driving force required for the respective load condition can be guaranteed by continuously adapting the drive wheel pressure to the load conditions.
  • the object is achieved in that the lifting cylinder is arranged using its lifting force in opposite directions, directly between the lifting frame part of the truck and the lever parallelogram suspension.
  • the frame part which can be raised is designed as a load frame-fixed support and guide plate for a lifting piston of the lifting cylinder, as a result of which the latter is optimally supported and guided in a simple manner.
  • the lifting cylinder for support in the lowering direction is rotatably mounted in the lever parallelogram suspension in a certain lever ratio and at least part of its supporting force can be transmitted to the drive unit via one of two lever arms formed by the bearing point, which necessitates use excludes electrical or hydraulic additional elements.
  • the supporting force of the lifting cylinder is provided depending on the load in order to increase the ground contact pressure of a drive wheel of the drive unit.
  • the lifting cylinder is provided with a freewheel, which allows the drive unit to be deflected vertically downward when the lifting truck is lowered.
  • the freewheel designed as a residual stroke provided between the upper side of the support and guide plate and the upper end of the lifting piston of the lifting cylinder, which expediently enables driving on uneven road surfaces with floor depressions without the ground contact pressure between the drive wheel and road surface being canceled
  • a preferred development of the invention is that the lifting cylinder for the preselectable change of the lever ratios on the transverse lever of the parallelogram suspension in the longitudinal direction of the pallet truck is manually and / or automatically displaceable and lockable, whereby the operator changed operating conditions and different road surfaces by superimposed and preselectable intervention on Pallet truck can take into account.
  • At least one compression spring is arranged between the non-lifting frame part and a drive-fixed component for the spring-loaded pretensioning of the drive unit. So that the device type, type and weight of the lifting truck can be adequately taken into account, the preload of the compression spring can be adjusted as desired, preferably by means of a clamping nut.
  • Figures 1 and 2 show a version of a pallet truck in the raised state with a known basic concept of the vehicle body.
  • This essentially consists of a frame part in the form of a drive frame 1 which cannot be raised and a frame part in the form of a load frame 2 arranged behind it and articulatedly connected thereto.
  • the drive frame 1 contains a drive unit 3 and is at its upwardly projecting end with a drawbar 4 equipped with which - in addition to the control of various vehicle functions - a drive wheel 5 arranged in the center on the underside of the drive frame 1 can be steered and braked in a known and therefore not shown and described manner.
  • the drive frame 1 is also carried by two substantially fixed castors 6. These are on both sides of the drive wheel 5 at the greatest possible distance from each other in a preferably welded to the drive frame 1
  • the bearing web 7 is mounted in order to counteract a tendency of the lifting truck to tip over.
  • the load frame 2 carries u. a. an energy supply unit 8 and is equipped with load carrying means in the form of two load arms 9. It is carried by load rollers 10, which are supported at the ends of the load arms 9 in pivotable wheel forks 11. These can be pivoted from a lowered to an elevated position by means of a pull or push linkage 12, indicated schematically by dot-dash lines, as a result of which the low lift (base lift) present in both embodiments of the lift truck can be effected.
  • a pull or push linkage 12 indicated schematically by dot-dash lines, as a result of which the low lift (base lift) present in both embodiments of the lift truck can be effected.
  • the drive wheel 5 is fastened to a gear 13, which is coupled to a drive motor 15 via a slewing ring bearing 14.
  • a gear plate 18 of rectangular cross-section is arranged above the slewing ring bearing 14 and with its outer ring 17, and in addition to a central bore 19 in its area opposite the load frame 2, it also has 2 smaller bores 22.
  • the traction motor 15 is flanged to the bearing inner ring 21 of the slewing ring bearing 14 by means of a lower motor flange 20.
  • Drive wheel 5 and gear 13 thus form a rotatable unit.
  • the clamping bolt 25 is secured at its two threaded ends with nuts 28, of which the one arranged above the upper spring plate 26 serves as an adjustable clamping nut. With their help, the pretension of the compression spring 27 can not only be preset as a function of the weight of the lifting truck, but can also be regulated in any manner as required.
  • a motor brake 31 flanged onto the traction motor 15 by means of an upper motor flange 30 can be designed as an electrical magnetic brake or instead as a mechanical brake that can be actuated from the drawbar 4.
  • a drawbar flange 32 Arranged above the motor brake 31 is a drawbar flange 32 which is screwed to the upper motor flange 30 by means of spacer bushes 33.
  • a drawbar structure 34 with a drawbar bearing 35 is supported on the housing formed in this way.
  • the articulated connection between the drive frame 1 and the load frame 2 is established via a parallelogram 36, 37, 38 arranged on both sides of the drive unit 3, which on the one hand consists of two upper rocker arms 36 and on the other hand is formed from two long lever legs 37 of a lower pair of angle levers 38.
  • One end of each rocker arm 36 is mounted in a housing projection 39 of the load frame 2, while its other end is articulated laterally on the drive frame 1.
  • Each angle lever 38 is mounted in a fastening plate 16, which in turn is fixed in the lower region of the side of the drive frame 2 which runs transversely to the longitudinal axis 40 of the lifting truck.
  • the pull or push linkage 12 schematically indicated in FIGS. 1 and 3 for the low lift (base lift) of the lifting truck is articulated in a short lever leg 57 of the angle lever 38.
  • the entire drive unit 3 is attached to the drive frame 1 on both sides by means of a parallelogram suspension (41, 42, 44) so as to be height-adjustable.
  • a parallelogram suspension (41, 42, 44) so as to be height-adjustable.
  • This consists of a pair of levers in the form of two mutually parallel cross levers 41 and 42, one end of which is mounted in bearing brackets 43 of the drive frame 1.
  • the other end of the cross levers 41, 42 is articulated on a longitudinal lever 44, which closes the lever parallelogram and is fastened, preferably welded, to the gear plate 18. Due to this articulated and flexible suspension, the drive unit 3 can perform the vertical movements necessary to compensate for uneven floors without losing contact with the ground (FIG. 5).
  • the lifting truck also has at least one, according to the exemplary embodiments shown in FIGS. 1-4, even two lifting cylinders 45 for the low lift (base lift) of the load frame 2.
  • the lifting cylinder 45 is arranged vertically and rotatably supported at its lower end in at least one of the two preferably horizontally extending cross levers 41 and 42.
  • the bearing point 46 is preferably selected so that the lever arm 47 directed towards the longitudinal lever 44 is longer than the lever arm 48 extending to the drive frame 1.
  • the upper end of the lifting cylinder 45 is held in a support and guide plate 49, which is preferably welded to the drive frame 1, the lifting piston 50 of the lifting cylinder 45 extending through a bearing bore 51 of the support and guide plate 49.
  • the lifting cylinder 45 is equipped with a freewheel 52 in such a way that even with the lifting piston 50 fully lowered, a residual stroke remains between its upper end and the upper side of the support and guide plate 49 (FIG. 5).
  • the drive frame 1 with the drive unit 3 of the high-lift truck shown in FIGS. 3 and 4 corresponds in terms of its structure to that of the low-lift truck described above according to FIGS. 1 and 2.
  • the load frame 2 differs in that it additionally carries a mast 53 , which is supported on a pair of wheel forks 54 and is provided with a height-adjustable lifting carriage 55, on which the actual load-carrying means 56 are arranged.
  • load forks any other load suspension means of other types, such.
  • B. swivel, push or swivel push forks are used.
  • the ground contact pressure required for the unloaded pallet truck between the drive wheel 5 and the road surface 1 is generated by the compression spring (s) 27. Since this ground contact pressure can vary depending on the type of device and the weight of the lifting truck, the preload force of the compression spring (s) 27 can be preset depending on these parameters using the clamping nut 28.
  • the lifting cylinder 45 With increasing load on the load frame 2, the lifting cylinder 45 is supported with its lifting piston 50 on the underside of the support and guide plate 49.
  • the resultant supporting force opposed to the lifting force is introduced via the bearing point 46 into the lower transverse lever 42 of the lever parallelogram suspension 41, 42, 44 and broken down into two force components in accordance with the lever ratio 47:48 present there.
  • a vertical deflection of the entire drive unit downwards is necessary in order to enable driving into floor depressions even when the lift truck is lowered without running the risk of possibly completely lifting the ground contact pressure between the drive wheel 5 and the road surface 29. This is achieved by the built-in freewheel 52 at the upper bearing point of the lifting cylinder 45, according to which the remaining stroke remaining as a reserve compensates for these uneven road surfaces.

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Abstract

In a lift truck, preferably a shaft-steered traveling lift truck with a drive unit (3) pre-tensioned by spring loading in the vertical direction, the drive unit is hinged, adjustably in height, by linkage parallelogram suspension (41, 42, 44) on a chassis part (1) of the lift truck which cannot be raised. To continuously adjust the drive wheel pressure to the useful load conditions, at least one lifting cylinder (45) of the working hydraulic system for the low lift (basic lift is arranged directly between a chassis part (49) that can be raised and the linkage parallelogram suspension (41, 42, 44), and its lower end is mounted in a horizontal transverse linkage (42). The support force of the lifting cylinder (45), which opposes the lifting force, is broken down according to a leverage ratio of lever (47) to lever (48) one force component is absorbed by the chassis part (1) that cannot be raised, and the other force component is transmitted directly to a drive wheel 5 of the drive unit 3 via a lever arm (47) in order to thus maintain the necessary driving and braking torque. In order for the drive unit (3) to be able to compensate for unevennesses of the ground even when the lift truck has been lowered, a lifting piston (50) of the lifting cylinder (45) has a free running segment (52) designed as residual stroke.

Description

Die Erfindung betrifft einen Hubwagen, vorzugsweise deichselgesteuerten Gehhubwagen, mit einer in vertikaler Richtung federbelastet vorgespannten Antriebseinheit, die mittels einer Hebelparallelogramm-Aufhängung an einem nicht anhebbaren Rahmenteil des Hubwagens höhenausgleichbar angelenkt und deren Bodenkontaktdruck lastkraf tabhängig variierbar ist und mit einem Hubzylinder für den Niederhub (Basishub) von anhebbaren Rahmenteilen.The invention relates to a pallet truck, preferably a drawbar-controlled pedestrian pallet truck, with a drive unit that is spring-loaded in the vertical direction, which is articulated in a height-adjustable manner by means of a lever parallelogram suspension on a frame part of the pallet truck that cannot be raised and whose ground contact pressure can be varied depending on the load force and with a lifting cylinder for the low lift (base stroke ) of liftable frame parts.

Aus der DE-PS 31 06 027 ist ein Hublader mit einem höhenausgleichbaren Radnabenantrieb bekannt, bei dem zwecks Verringerung des Kippmomentes mit zunehmender Hubhöhe und/oder Belastung die Vorspannung zumindest einer Feder eines verfederten Radnabenantriebes vermindert wird, wodurch der Bodenkontaktdruck in unbeladenem Zustand am größten und dadurch die Lenkung am schwergängigsten ist. Da mit dieser Einrichtung primär der Kippneigung des Fahrzeugs entgegengewirkt werden soll, beschränkt sich deren Einsatz vorrangig auf Hochhubwagen. Für Nieder­hubwagen ist dieses System weniger geeignet, da bei diesen Fahrzeugen in der Regel keine Kippgefahr besteht, sondern statt dessen eine Optimierung der Antriebs-, Lenk-, und Bremskräfte angestrebt wird. Insbesondere letztere dürften aufgrund des sich mit steigender Zuladung stetig verringernden Bodenkontaktes in Frage gestellt sein. Abgesehen davon ist diese Einrichtung aufgrund des Einsatzes aufwendiger hydraulischer Mittel störanfällig und wartungsintensiv und deren Anwendungsbereich auf Hublader der Bauart beschränkt, die mit Radnabenantrieben ausgestattet sind.From DE-PS 31 06 027 a lift truck with a height-adjustable wheel hub drive is known, in which, in order to reduce the tilting moment with increasing lifting height and / or load, the pretension of at least one spring of a spring-loaded wheel hub drive is reduced, as a result of which the ground contact pressure is greatest and unloaded this makes steering the most difficult. Since this device is primarily intended to counteract the tendency of the vehicle to tip over, its use is primarily restricted to high-lift trucks. This system is less suitable for pallet trucks, since there is generally no danger of tipping over with these vehicles, but instead an optimization of the drive, steering and braking forces is sought. The latter, in particular, are likely to be called into question due to the steadily decreasing ground contact with increasing payload. Apart from this, this device is susceptible to malfunction and maintenance-intensive due to the use of complex hydraulic means and its area of application is limited to a lift truck of the type which is equipped with wheel hub drives.

Bei einem anderen in der EP-AO 150 830 offenbarten deichselgelenkten Fördergerät wird ein zwischen zwei seitlichen Stutzrädern angeordnetes Antriebsrad durch vorspannbare Federmittel in Bodeneingriff gedrückt, wobei die Grundeinstellung des Antriebsraddruckes möglichst gering gehalten und über eine komplizierte Vorspann­einrichtung mit einer Vielzahl elektrohydraulischer Stellelemente in Abhängigkeit von einem bestimmten Betriebsparamenter - vorzugsweise einem Bremsvorgang­einleitungssignal - erhöht wird. Als alternative Betriebsparameter können statt dessen die Fahrbahnneigung, das Belastungsmoment des Antriebsmotors, die Boden­beschaffenheit oder ein manuell auslösbares Willkürsignal herangezogen werden. Dieser Einrichtung hängt der Nachteil an, daß die ständig variierenden Belastungszustände des Fördergerätes nicht ausreichend berücksichtigt werden. Obwohl die Deichsel für den Bedienungsmann fast durchweg leichtgängig bedienbar bleibt, ist es aus sicherheits­technischen Gründen äußerst fraglich, den unter allen Umständen einzuhaltenden Bremsweg von der Funktion einer Vielzahl elektro-hydraulischer Stellelemente, wie z. B. Schalter, Ventile, Hydrospeicher und Hydraulikzylinder, abhängig zu machen, da bei einem Ausfall eines derselben der zum Einhalten des Bremsweges erforderliche Antriebs­raddruck gegenüber der Fahrbahn aufgehoben wird und das Antriebsrad in einer Art Gleitreibung durchrutschen kann, wodurch die Gefahr besteht, daß der Bremsweg in unzulässiger Weise verlängert wird.In another drawbar-steered conveying device disclosed in EP-AO 150 830, a drive wheel arranged between two lateral support wheels is pressed into ground engagement by prestressable spring means, the basic setting of the drive wheel pressure being kept as low as possible and by means of a complicated prestressing device with a large number of electrohydraulic adjusting elements depending on one certain operating parameters - preferably a brake initiation signal - is increased. Instead, the road inclination, the loading torque of the drive motor, the condition of the ground or a manually triggered arbitrary signal can be used as alternative operating parameters. The disadvantage of this device is that the constantly varying load conditions of the conveyor are not sufficiently taken into account. Although the tiller remains easy to operate for the operator almost entirely, it is extremely questionable for safety reasons that the braking distance to be maintained under all circumstances depends on the function of a large number of electro-hydraulic actuating elements, such as. B. switches, valves, hydraulic accumulator and hydraulic cylinder, depending, because in the event of a failure of one of the drive wheel pressure required to maintain the braking distance to the roadway is canceled and the drive wheel can slip in a kind of sliding friction, which creates the risk that the braking distance is extended in an impermissible manner.

Gemäß einer in der EP-AO 209 502 beschriebenen Vorrichtung zum Erhöhen der Bremskraft in industriellen Förderwagen ist bereits die Bedeutung der Abhängigkeit des Brems­vorganges von den unterschiedlichen Ladezuständen des Förderwagens erkannt worden. Aufgrund dessen wird dort schon sinnvollerweise die Zuladung des Förderwagens bei der Erhöhung des Antriebsraddruckes berucksichtigt, in der Form, daß die Federvorspannung einer Feder einer elastisch aufgehängten Antriebseinheit über eine separate hydraulische Verstelleinrichtung belastungsabhängig erhöht wird, um dadurch den Antriebsraddruck zu vergrößern. Diese Einrichtung erscheint in ihrem Aufbau und ihrer Funktion relativ kompliziert, was neben erheblichen Herstellungs­kosten auch mit einer eingeschränkten Betriebssicherheit infolge nicht auszuschließender Störanfälligkeit durch Fehlfunktion oder Versagen eines hydraulischen Stellgliedes verbunden ist.According to a device for increasing the braking force in industrial trolleys described in EP-AO 209 502, the importance of the dependence of the braking process on the different charging states of the vehicle is already significant Tram has been recognized. Because of this, the payload of the trolley is usefully taken into account when increasing the drive wheel pressure, in the form that the spring preload of a spring of an elastically suspended drive unit is increased depending on the load via a separate hydraulic adjusting device, in order to thereby increase the drive wheel pressure. This device appears to be relatively complicated in terms of its structure and function, which, in addition to considerable manufacturing costs, is also associated with limited operational safety as a result of malfunctioning due to malfunction or failure of a hydraulic actuator.

Der Erfindung liegt die Aufgabe zugrunde, bei einem Hubwagen der gattungsgemäßen Art mit einem Minimum an Aufwand und Herstellungskosten eine einfach funktionierende und dadurch betriebssichere Einrichtung zu schaffen, mit der einerseits die erforderliche Lenkkraft für die mit dem Antrieb verbundene Fahrdeichsel während des Fahrbetriebes minimiert und andererseits die für den jeweiligen Belastungszustand erforderliche Brems- bzw. Antriebskraft durch eine kontinuierliche Anpassung des Antriebsraddruckes an die Lastverhältnisse gewährleistet werden kann.The invention has for its object to provide a simple functioning and therefore reliable device in a pallet truck of the generic type with a minimum of effort and manufacturing costs, with which on the one hand minimizes the steering force required for the drawbar connected to the drive during operation and on the other hand the the braking or driving force required for the respective load condition can be guaranteed by continuously adapting the drive wheel pressure to the load conditions.

Die derart gestellte Aufgabe wird erfindungsgemäß dadurch gelöst, daß der Hubzylinder sich unter Ausnutzung seiner Hubkraft gegensinnig abstützend direkt zwischen dem anhebbaren Rahmenteil des Hubwagens und der Hebel­parallelogramm-Aufhängung angeordnet ist. Die rein mechanische Ausnutzung der von der in jedem Hubwagen ohnehin vorhandenen Arbeitshydraulik erzeugten Kräfte zur Aufrechterhaltung des sowohl zur Übertragung des Antriebs- als auch des Bremsmomentes erforderlichen Bodenkontaktdruckes stellt zweifelsohne eine besonders kostengünstige Lösung dar, die sich nicht nur durch hohe Betriebssicherheit sondern insbesondere auch durch geringen Wartungsbedarf auszeichnet.The object is achieved in that the lifting cylinder is arranged using its lifting force in opposite directions, directly between the lifting frame part of the truck and the lever parallelogram suspension. The purely mechanical exploitation of the forces generated by the working hydraulics that are present in every pallet truck to maintain the ground contact pressure required for the transmission of the drive torque as well as the braking torque is undoubtedly a particularly cost-effective solution, which is characterized not only by high operational reliability but in particular also by low maintenance requirements.

Gemäß einer vorteilhaften Ausgestaltung der Erfindung ist zur Abstutzung des Hubzylinders in Hubrichtung das anhebbare Rahmenteil als lastrahmenfixierte Stütz- und Führungsplatte für einen Hubkolben des Hubzylinders ausgebildet, wodurch derselbe in einfacher Weise optimal gestützt und geführt wird.According to an advantageous embodiment of the invention, in order to support the lifting cylinder in the lifting direction, the frame part which can be raised is designed as a load frame-fixed support and guide plate for a lifting piston of the lifting cylinder, as a result of which the latter is optimally supported and guided in a simple manner.

In besonders sinnvoller geometrischer Anordnung der Bauelemente ist der Hubzylinder zur Abstützung in Senkrichtung in einem bestimmten Hebelverhältnis in der Hebelparallelogramm-Aufhängung drehbar gelagert und zumindest ein Teil seiner Abstützkraft über einen von zwei durch den Lagerpunkt gebildeten Hebelarme auf die Antriebseinheit übertragbar, was das Erfordernis der Verwendung elektrischer oder hydraulischer Zusatzelemente ausschließt.In a particularly sensible geometric arrangement of the components, the lifting cylinder for support in the lowering direction is rotatably mounted in the lever parallelogram suspension in a certain lever ratio and at least part of its supporting force can be transmitted to the drive unit via one of two lever arms formed by the bearing point, which necessitates use excludes electrical or hydraulic additional elements.

Zur Berücksichtigung unterschiedlicher Nutzlastverhältnisse ist die Abstützkraft des Hubzylinders beladungsabhängig zur Vergrößerung des Bodenkontaktdruckes eines Antriebs­rades der Antriebseinheit vorgesehen.In order to take into account different payload ratios, the supporting force of the lifting cylinder is provided depending on the load in order to increase the ground contact pressure of a drive wheel of the drive unit.

In Weiterbildung des Erfindungsgedankens ist der Hubzylinder mit einem Freilauf versehen, der bei abgesenktem Hubwagen ein Auslenken der Antriebseinheit vertikal nach unten ermöglicht. Dabei ist der Freilauf als zwischen der Oberseite der Stütz- und Führungsplatte und dem oberen Ende des Hubkolbens des Hubzylinders vorgesehener Resthub ausgebildet, wodurch zweckmäßigerweise ein Befahren unebener Fahrbahnoberflächen mit Boden­vertiefungen ermöglicht wird, ohne daß sich der Bodenkontaktdruck zwischen Antriebsrad und Fahrbahn­oberfläche aufhebtIn a further development of the inventive concept, the lifting cylinder is provided with a freewheel, which allows the drive unit to be deflected vertically downward when the lifting truck is lowered. Here is the freewheel designed as a residual stroke provided between the upper side of the support and guide plate and the upper end of the lifting piston of the lifting cylinder, which expediently enables driving on uneven road surfaces with floor depressions without the ground contact pressure between the drive wheel and road surface being canceled

Eine bevorzugte Weiterbildung der Erfindung besteht darin, daß der Hubzylinder zwecks vorwählbarer Veränderung der Hebelverhältnisse am Querhebel der Parallelogramm-­Aufhängung in Längsrichtung des Hubwagens manuell und/oder automatisch verschiebbar und arretierbar ist, wodurch der Bedienungsmann geänderten Betriebszuständen und unterschiedlichen Fahrbahnoberflächen durch überlagerten und vorwählbaren Stelleingriff am Hubwagen Rechnung tragen kann.A preferred development of the invention is that the lifting cylinder for the preselectable change of the lever ratios on the transverse lever of the parallelogram suspension in the longitudinal direction of the pallet truck is manually and / or automatically displaceable and lockable, whereby the operator changed operating conditions and different road surfaces by superimposed and preselectable intervention on Pallet truck can take into account.

Zwecks Grundeinstellung des für den unbeladenen Hubwagen notwendigen Antriebsraddruckes ist zur federbelasteten Vorspannung der Antriebseinheit zwischen dem nichtanhebbaren Rahmenteil und einem antriebsfesten Bauteil zumindest eine Druckfeder angeordnet. Damit Gerätetype, Bauart und Eigengewicht des Hubwagens ausreichend berücksichtigt werden können, ist die Vorspannung der Druckfeder, vorzugsweise mittels einer Spannmutter, beliebig einstellbar.For the basic setting of the drive wheel pressure necessary for the unloaded lifting truck, at least one compression spring is arranged between the non-lifting frame part and a drive-fixed component for the spring-loaded pretensioning of the drive unit. So that the device type, type and weight of the lifting truck can be adequately taken into account, the preload of the compression spring can be adjusted as desired, preferably by means of a clamping nut.

Weitere vorteilhafte Ausgestaltungen der Erfindung sind in den Ansprüchen 5-7 sowie in der nachfolgenden Beschreibung niedergelegt.Further advantageous embodiments of the invention are set out in claims 5-7 and in the description below.

Die Erfindung läßt mehrere Ausführungsformen zu, von denen zwei exemplarisch in den Figuren dargestellt und nachfolgend beschrieben werden. Es zeigt:

  • Fig. 1 eine Seitenansicht eines Niederhubwagens im angehobenem Zustand mit schematisch dargestelltem Antrieb,
  • Fig. 2 eine Draufsicht auf den Niederhubwagen gemäß Fig. 1,
  • Fig. 3 eine Seitenansicht eines Hochhubwagens mit angehobenem Basishub und schematisch dargestelltem Antrieb,
  • Fig. 4 eine Draufsicht auf den Hochhubwagen gemäß Fig. 3,
  • Fig. 5 eine detaillierte Darstellung des Antriebes als Ausschnitt der Figuren 1 und 3.
The invention permits several embodiments, two of which are illustrated by way of example in the figures and described below. It shows:
  • 1 is a side view of a pallet truck in the raised state with a schematically illustrated drive,
  • 2 is a plan view of the pallet truck according to FIG. 1,
  • 3 shows a side view of a high-lift truck with a raised base stroke and a schematically illustrated drive,
  • 4 shows a top view of the pallet truck according to FIG. 3,
  • 5 shows a detailed illustration of the drive as a detail from FIGS. 1 and 3.

Die Figuren 1 und 2 zeigen eine Ausführung eines Niederhubwagens im angehobenem Zustand mit bekannter Grundkonzeption des Fahrzeugaufbaus. Dieser besteht im wesentlichen aus einem nicht anhebbaren Rahmenteil in Form eines Antriebsrahmens 1 und einem dahinter angeordneten und mit diesem gelenkig verbundenen, anhebbaren Rahmenteil in Form eines Lastrahmens 2. Der Antriebs­rahmen 1 beinhaltet eine Antriebseinheit 3 und ist an seinem nach oben ragenden Ende mit einer Fahrdeichsel 4 ausgestattet, mit der sich - neben der Steuerung diverser Fahrzeugfunktionen - ein mittig an der Unterseite des Antriebsrahmens 1 angeordnetes Antriebsrad 5 in bekannter und deshalb nicht näher dargestellter und beschriebener Weise lenken und bremsen läßt. Der Antriebsrahmen 1 wird außerdem von zwei im wesentlichen festen Schwenkrollen 6 getragen. Diese sind beidseitig des Antriebsrades 5 in größtmöglichem Abstand zueinander in einem am Antriebsrahmen 1 befestigten, vorzugsweise angeschweißten Lagersteg 7 gelagert, um einer Kippneigung des Hubwagens entgegenzuwirken.Figures 1 and 2 show a version of a pallet truck in the raised state with a known basic concept of the vehicle body. This essentially consists of a frame part in the form of a drive frame 1 which cannot be raised and a frame part in the form of a load frame 2 arranged behind it and articulatedly connected thereto. The drive frame 1 contains a drive unit 3 and is at its upwardly projecting end with a drawbar 4 equipped with which - in addition to the control of various vehicle functions - a drive wheel 5 arranged in the center on the underside of the drive frame 1 can be steered and braked in a known and therefore not shown and described manner. The drive frame 1 is also carried by two substantially fixed castors 6. These are on both sides of the drive wheel 5 at the greatest possible distance from each other in a preferably welded to the drive frame 1 The bearing web 7 is mounted in order to counteract a tendency of the lifting truck to tip over.

Der Lastrahmen 2 trägt u. a. eine Energieversorgungseinheit 8 und ist mit Lasttragemitteln in Form zweier Lastarme 9 ausgestattet. Er wird von Lastrollen 10 getragen, welche endseitig der Lastarme 9 in schwenkbaren Radgabeln 11 gelagert sind. Diese sind über ein schematisch strichpunktiert angedeutetes Zug- oder Druckgestänge 12 von einer abgesenkten in eine erhöhte Lage verschwenkbar, wodurch sich der in beiden Ausführungsformen des Hubwagens vorhandene Niederhub (Basishub) bewirken läßt. Dabei kann es bauartbedingt auch zweckmäßig sein, die Energieversorgungseinheit 8 dem nicht anhebbaren Antriebsrahmen 1 zuzuordnen und/oder Lasttragemittel anderer bekannter Bauart, beispielsweise mit mehreren Freiheitsgraden, einzusetzen.The load frame 2 carries u. a. an energy supply unit 8 and is equipped with load carrying means in the form of two load arms 9. It is carried by load rollers 10, which are supported at the ends of the load arms 9 in pivotable wheel forks 11. These can be pivoted from a lowered to an elevated position by means of a pull or push linkage 12, indicated schematically by dot-dash lines, as a result of which the low lift (base lift) present in both embodiments of the lift truck can be effected. Depending on the design, it may also be expedient to assign the power supply unit 8 to the drive frame 1, which cannot be raised, and / or to use load-bearing means of another known type, for example with several degrees of freedom.

Die im Antriebsrahmen 1 untergebrachte Antriebseinheit 3 zeigt von unten nach oben gesehen im wesentlichen folgenden Aufbau auf, der in Fig. 5 dargestellt ist.The drive unit 3 accommodated in the drive frame 1, viewed from the bottom upwards, essentially shows the following structure, which is shown in FIG. 5.

Das Antriebsrad 5 ist an einem Getriebe 13 befestigt, das über ein Drehkranzlager 14 mit einem Fahrmotor 15 gekoppelt ist. Über dem Drehkranzlager 14 und mit dessen Außenring 17 fest verbunden ist eine Getriebeplatte 18 rechteckigen Querschnitts angeordnet, die neben einer mittigen Bohrung 19 in ihrem dem Lastrahmen 2 entgegengesetzten Bereich noch 2 kleinere Bohrungen 22 aufweist. In der mittigen Bohrung 19 ist der Fahrmotor 15 mittels eines unteren Motorf lansches 20 an den Lagerinnenring 21 des Drehkranzlagers 14 angeflanscht. Antriebsrad 5 und Getriebe 13 bilden dergestalt eine zusammen verdrehbare Einheit.The drive wheel 5 is fastened to a gear 13, which is coupled to a drive motor 15 via a slewing ring bearing 14. A gear plate 18 of rectangular cross-section is arranged above the slewing ring bearing 14 and with its outer ring 17, and in addition to a central bore 19 in its area opposite the load frame 2, it also has 2 smaller bores 22. In the central bore 19, the traction motor 15 is flanged to the bearing inner ring 21 of the slewing ring bearing 14 by means of a lower motor flange 20. Drive wheel 5 and gear 13 thus form a rotatable unit.

Unterhalb der Getriebeplatte 18 sind am Antriebsrahmen 1 zwei als Flachteile ausgebildete Spannplatten 23 befestigt. In diese sind vertikal fluchtend zu den Bohrungen 22 ebenfalls Bohrungen 24 gleichen Durchmessers eingebracht. Durch die Bohrungen 22 und 24 erstreckt sich ein beidseitig mit Gewindeenden versehener Spannbolzen 25, auf dem über der Getriebeplatte 18 zwischen zwei Federtellern 26 zumindest ein Federmittel 27 angeordnet ist, das im Ausführungsbeispiel gemäß Figur 5 als Druckfeder ausgebildet ist. In Abhängigkeit von der Fahrzeugtype können bauartbedingt statt dessen auch Tellerfedern oder hydraulische, pneumatische bzw. hydropneumatische Federmittel 27 zur Anwendung kommen.Below the gear plate 18 are two on the drive frame 1 Clamping plates 23 designed as flat parts are attached. Bores 24 of the same diameter are also introduced into these in a vertical alignment with the bores 22. Extending through the bores 22 and 24 is a tensioning bolt 25 provided on both sides with threaded ends, on which at least one spring means 27 is arranged above the gear plate 18 between two spring plates 26, which spring spring is designed as a compression spring in the exemplary embodiment according to FIG. Depending on the type of vehicle, disc springs or hydraulic, pneumatic or hydropneumatic spring means 27 can also be used instead.

Der Spannbolzen 25 ist an seinen beiden Gewindeenden mit Muttern 28 gesichert, von denen die über dem oberen Federteller 26 angeordnete als verstellbare Spannmutter dient. Mit deren Hilfe läßt sich die Vorspannung der Druckfeder 27 in Abhängigkeit vom Eigengewicht des Hubwagens nicht nur voreinstellen, sondern bei Bedarf jederzeit in beliebiger Weise regulieren. Eine mittels eines oberen Motorflansches 30 auf den Fahrmotor 15 aufgeflanschte Motorbremse 31 kann als elektrische Magnetbremse oder statt dessen auch als von der Deichsel 4 aus betätigbare mechanische Bremse ausgebildet sein.The clamping bolt 25 is secured at its two threaded ends with nuts 28, of which the one arranged above the upper spring plate 26 serves as an adjustable clamping nut. With their help, the pretension of the compression spring 27 can not only be preset as a function of the weight of the lifting truck, but can also be regulated in any manner as required. A motor brake 31 flanged onto the traction motor 15 by means of an upper motor flange 30 can be designed as an electrical magnetic brake or instead as a mechanical brake that can be actuated from the drawbar 4.

Oberhalb der Motorbremse 31 ist ein Deichselflansch 32 angeordnet, der mittels Distanzbüchsen 33 mit dem oberen Motorflansch 30 verschraubt ist. Auf dem derart gebildeten Gehäuse stützt sich ein Deichselaufbau 34 mit einem Deichsel­lager 35 ab.Arranged above the motor brake 31 is a drawbar flange 32 which is screwed to the upper motor flange 30 by means of spacer bushes 33. A drawbar structure 34 with a drawbar bearing 35 is supported on the housing formed in this way.

Die gelenkige Verbindung zwischen Antriebsrahmen 1 und Lastrahmen 2 wird über ein beidseitig der Antriebseinheit 3 angeordnetes Parallelogramm 36, 37, 38, hergestellt, das einerseits aus zwei oberen Schwinghebeln 36 und andererseits aus zwei langen Hebelschenkeln 37 eines unteren Winkelhebel­paares 38 gebildet wird. Das eine Ende eines jeden Schwinghebels 36 ist in einer Gehäuseausladung 39 des Lastrahmens 2 gelagert, während ihr anderes Ende seitlich am Antriebsrahmen 1 angelenkt ist. Jeder Winkelhebel 38 ist in einer Befestigungsplatte 16 gelagert, die ihrerseits im unteren Bereich der quer zur Längs­achse 40 des Hubwagens verlaufenden Seite des Antriebsrahmen 2 fixiert ist. In einem kurzen Hebelschenkel 57 des Winkelhebels 38 ist das in den Figuren 1 und 3 schematisch angedeutete Zug- oder Druckgestänge 12 für den Niederhub (Basishub) des Hubwagens angelenkt.The articulated connection between the drive frame 1 and the load frame 2 is established via a parallelogram 36, 37, 38 arranged on both sides of the drive unit 3, which on the one hand consists of two upper rocker arms 36 and on the other hand is formed from two long lever legs 37 of a lower pair of angle levers 38. One end of each rocker arm 36 is mounted in a housing projection 39 of the load frame 2, while its other end is articulated laterally on the drive frame 1. Each angle lever 38 is mounted in a fastening plate 16, which in turn is fixed in the lower region of the side of the drive frame 2 which runs transversely to the longitudinal axis 40 of the lifting truck. The pull or push linkage 12 schematically indicated in FIGS. 1 and 3 for the low lift (base lift) of the lifting truck is articulated in a short lever leg 57 of the angle lever 38.

Die gesamte Antriebseinheit 3 ist beidseitig mittels je einer Parallelogramm-Aufhängung (41, 42, 44) am Antriebsrahmen 1 höhenausgleichbar befestigt. Diese besteht aus einem Hebelpaar in Form zweier parallel zueinander verlaufender Querhebel 41 und 42, deren eines Ende in Lagerlaschen 43 des Antriebsrahmens 1 gelagert ist. Das andere Ende der Querhebel 41, 42 ist an einem Längshebel 44 angelenkt, der das Hebelparallelogramm schließt und an der Getriebeplatte 18 befestigt, vorzugsweise angeschweißt ist. Durch diese gelenkige und höhennachgiebige Aufhängung kann die Antriebseinheit 3 die zum Ausgleich von Bodenunebenheiten notwendigen Vertikalbewegungen ausführen ohne den Bodenkontakt zu verlieren (Fig. 5).The entire drive unit 3 is attached to the drive frame 1 on both sides by means of a parallelogram suspension (41, 42, 44) so as to be height-adjustable. This consists of a pair of levers in the form of two mutually parallel cross levers 41 and 42, one end of which is mounted in bearing brackets 43 of the drive frame 1. The other end of the cross levers 41, 42 is articulated on a longitudinal lever 44, which closes the lever parallelogram and is fastened, preferably welded, to the gear plate 18. Due to this articulated and flexible suspension, the drive unit 3 can perform the vertical movements necessary to compensate for uneven floors without losing contact with the ground (FIG. 5).

Wie alle Hubfahrzeuge weist auch der Hubwagen zumindest einen, gemäß den in den Figuren 1-4 dargestellten Ausführungsbeispielen sogar zwei Hubzylinder 45 für den Niederhub (Basishub) des Lastrahmens 2 auf. Der Hubzylinder 45 ist vertikal angeordnet und an seinem unteren Ende zumindest in einem der beiden vorzugsweise horizontal verlaufenden Querhebel 41 bzw. 42 drehbar gelagert. Durch die Wahl der Anordnung des Lagerpunktes 45, der sich in dem in Figur 5 dargestellten Antrieb auf dem unteren Querhebel 42 befindet, wird dieser in zwei Hebelarme 47 und 48 unterteilt. Dabei wird der Lagerpunkt 46 vorzugsweise so gewählt, daß der zum Längshebel 44 gerichtete Hebelarm 47 länger ist als der zum Antriebsrahmen 1 verlaufende Hebelarm 48.Like all lifting vehicles, the lifting truck also has at least one, according to the exemplary embodiments shown in FIGS. 1-4, even two lifting cylinders 45 for the low lift (base lift) of the load frame 2. The lifting cylinder 45 is arranged vertically and rotatably supported at its lower end in at least one of the two preferably horizontally extending cross levers 41 and 42. By choosing the arrangement of the bearing point 45, which is in the drive shown in Figure 5 on the lower cross lever 42, this is divided into two lever arms 47 and 48. The bearing point 46 is preferably selected so that the lever arm 47 directed towards the longitudinal lever 44 is longer than the lever arm 48 extending to the drive frame 1.

Das obere Ende des Hubzylinders 45 wird in einer am Antriebs­rahmen 1 fixierten, vorzugsweise angeschweißten Stütz- und Führungsplatte 49 gehalten, wobei sich der Hubkolben 50 des Hubzylinders 45 durch eine Lagerbohrung 51 der Stütz- und Fuhrungsplatte 49 erstreckt. Der Hubzylinder 45 ist mit einem Freilauf 52 ausgestattet, dergestalt, daß auch noch bei voll abgesenktem Hubkolben 50 zwischen dessen oberem Ende und der Oberseite der Stütz- und Führungsplatte 49 ein Resthub verbleibt (Fig. 5).The upper end of the lifting cylinder 45 is held in a support and guide plate 49, which is preferably welded to the drive frame 1, the lifting piston 50 of the lifting cylinder 45 extending through a bearing bore 51 of the support and guide plate 49. The lifting cylinder 45 is equipped with a freewheel 52 in such a way that even with the lifting piston 50 fully lowered, a residual stroke remains between its upper end and the upper side of the support and guide plate 49 (FIG. 5).

Der Antriebsrahmen 1 mit der Antriebseinheit 3 des in den Fig. 3 und 4 dargestellten Hochhubwagens entspricht von seinem Aufbau her dem des zuvor beschriebenen Niederhubwagens gemäß den Fig. 1 und 2. Dagegen unterscheidet sich der Lastrahmen 2 dadurch, daß er zusätzlich einen Hubmast 53 trägt, der sich auf einem Radgabelpaar 54 abstützt und mit einem höhenbeweglichen Hubschlitten 55 versehen ist, an dem die eigentlichen Lasttragemittel 56 angeordnet sind. Obwohl im Ausführungs­beispiel vereinfacht als Lastgabeln ausgebildet, können statt dessen selbstverständlich jegliche Lastaufnahmemittel anderer Bauart, wie z. B. Schwenk-, Schub oder Schwenkschubgabeln zum Einsatz kommen.The drive frame 1 with the drive unit 3 of the high-lift truck shown in FIGS. 3 and 4 corresponds in terms of its structure to that of the low-lift truck described above according to FIGS. 1 and 2. In contrast, the load frame 2 differs in that it additionally carries a mast 53 , which is supported on a pair of wheel forks 54 and is provided with a height-adjustable lifting carriage 55, on which the actual load-carrying means 56 are arranged. Although simplified in the embodiment as load forks, of course, any other load suspension means of other types, such. B. swivel, push or swivel push forks are used.

Die Wirkungsweise des erfindungsgemäßen Antriebes wird nachfolgend näher erläutert.The mode of operation of the drive according to the invention is explained in more detail below.

Der für den unbeladenen Hubwagen notwendige Bodenkontaktdruck zwischen dem Antriebsrad 5 und der Fahrbahnoberfläche 1 wird durch die Druckfeder(n) 27 erzeugt. Da dieser Bodenkontaktdruck in Abhängigkeit von der Gerätetype und dem Eigengewicht des Hubwagens variieren kann, läßt sich die Vorspannkraft der Druckfeder(n) 27 in Abhängigkeit von diesen Parametern anhand der Spannmutter 28 voreinstellen. Mit steigender Zuladung auf dem Lastrahmen 2 stützt sich der Hubzylinder 45 mit seinem Hubkolben 50 an der Unterseite der Stütz- und Führungsplatte 49 ab. Die daraus resultierende, der Hubkraft entgegengerichtete Abstützkraft wird Ober den Lagerpunkt 46 in den unteren Querhebel 42 der Hebelparallelogramm-Aufhängung 41, 42, 44 eingeleitet und entsprechend dem dort vorhandenen Hebel­verhältnis 47:48 in zwei Kraftkomponenten zerlegt. Während die größere der derart erzeugten Kraftkomponenten Ober den kurzen Hebelarm 48 in den Antriebsrahmen 1 eingeleitet und von diesem aufgenommen wird, wird die kleinere der Kraft­komponenten Ober den längeren Hebelarm 47 direkt auf die Antriebseinheit 3 übertragen, wodurch sich der Bodenkontaktdruck des Antriebsrades 5 erhöht. Dabei hat es sich als zweckmäßig erwiesen, das eingebaute Hebelverhältnis 47:48 nicht nur rechnerisch, sondern auch empirisch zu ermitteln.The ground contact pressure required for the unloaded pallet truck between the drive wheel 5 and the road surface 1 is generated by the compression spring (s) 27. Since this ground contact pressure can vary depending on the type of device and the weight of the lifting truck, the preload force of the compression spring (s) 27 can be preset depending on these parameters using the clamping nut 28. With increasing load on the load frame 2, the lifting cylinder 45 is supported with its lifting piston 50 on the underside of the support and guide plate 49. The resultant supporting force opposed to the lifting force is introduced via the bearing point 46 into the lower transverse lever 42 of the lever parallelogram suspension 41, 42, 44 and broken down into two force components in accordance with the lever ratio 47:48 present there. While the larger of the force components generated in this way is introduced via the short lever arm 48 into the drive frame 1 and is received by the latter, the smaller of the force components is transmitted directly to the drive unit 3 via the longer lever arm 47, as a result of which the ground contact pressure of the drive wheel 5 increases. It has proven useful to determine the built-in leverage ratio 47:48 not only mathematically but also empirically.

Es versteht sich von selbst, daß mit steigender Nutzlast-­Zuladung die Abstützkraft des Hubzylinders 45 und somit auch die auf das Antriebsrad 5 übertragene zusätzliche Kraft­komponente in dem Maße zunimmt, daß der für den Antrieb und die Bremsung erforderliche, jeweilige Bodenkontaktdruck zwischen dem Antriebsrad 5 und der Fahrbahnoberfläche 29 stets gewährleistet ist. Da das durch Bodenunebenheiten verursachte geringfügige Heben und Senken der Lasttragemitteln 9 bzw. 56 gleichermaßen um das eingebaute Hebelverhältnis 47:48 des unteren Querhebels 42 reduziert wird, ist es von untergeordneter Bedeutung und für den eigentlichen Transport des Ladegutes unerheblich.It goes without saying that as the payload increases, the support force of the lifting cylinder 45 and thus also the additional force component transmitted to the drive wheel 5 increases to the extent that the respective ground contact pressure required for the drive and braking between the drive wheel 5 and the road surface 29 is always guaranteed. Since the slight lifting and lowering of the load-carrying means 9 and 56 caused by uneven floors is equally reduced by the built-in lever ratio 47:48 of the lower transverse lever 42, it is of secondary importance and for the actual transport of the cargo irrelevant.

Um auch bei abgesenktem Hubwagen ein Befahren von Boden­vertiefungen zu ermöglichen ohne dabei Gefahr zu laufen, gegebenenfalls den Bodenkontaktdruck zwischen dem Antriebsrad 5 und der Fahrbahnoberfläche 29 ganz aufzuheben, ist ein vertikales Auslenken der gesamten Antriebseinheit nach unten erforderlich. Dies wird durch den eingebauten Freilauf 52 an der oberen Lagerstelle des Hubzylinders 45 erreicht, gemäß dem der als Reserve verbleibende Resthub diese Fahrbahnunebenheiten egalisiert.A vertical deflection of the entire drive unit downwards is necessary in order to enable driving into floor depressions even when the lift truck is lowered without running the risk of possibly completely lifting the ground contact pressure between the drive wheel 5 and the road surface 29. This is achieved by the built-in freewheel 52 at the upper bearing point of the lifting cylinder 45, according to which the remaining stroke remaining as a reserve compensates for these uneven road surfaces.

Somit wird durch die erfindungsgemäße, sinnvolle geometrische Anordnung der ohnehin im Hubwagen vorhandenen, wesentlichen Bauelemente unter zweckmäßiger Ausnutzung der Abstutzkräfte des Hubzylinders 45 eine besonders kostengünstige Lösung der zugrundegelegten Aufgabe erreicht. Diese zeichnet sich insbesondere durch ihre Einfachheit infolge Verzichts auf jegliche elektrischen, hydraulischen oder elektro­hydraulischen Zusatzelemente aus, wodurch nicht nur eine kostengünstige, sondern darüber hinaus noch äußerst betriebs­sichere und relativ wartungsfreie Einrichtung geschaffen wird.Thus, a particularly cost-effective solution to the underlying task is achieved by the sensible geometric arrangement according to the invention of the essential components which are already present in the lifting truck, with appropriate use of the supporting forces of the lifting cylinder 45. This is characterized in particular by its simplicity due to the omission of any electrical, hydraulic or electrohydraulic additional elements, as a result of which not only an inexpensive, but also extremely reliable and relatively maintenance-free device is created.

Die Erfindung ist selbstverständlich nicht auf die in den Figuren dargestellten und in der Beschreibung niedergelegten Ausführungsbeispiele beschränkt. Es versteht sich von selbst, daß zahlreiche konstruktive Abwandlungen im Rahmen der Erfindung liegen. So ist es denkbar, die Antriebsaufhängung auf Hubwagen bzw. Fördergeräte anderer Bauart zu übertragen, beispielsweise auf solche, bei denen der Bedienungsmann auf dem Fahrzeug mitfährt. Ebenso ist es im Rahmen des Fachmännischen möglich, den Hubzylinder 45 in Längsachse des Hubwagens durch bekannte mechanische, elektrische, hydraulische oder pneumatische Mittel längsverschiebbar und arretierbar zu gestalten, um dadurch das Hebelverhältnis und somit den Bodenkontaktdruck des Antriebsrades 5 entsprechend den gegebenen Betriebsverhältnissen vorwählbar zu verändern, wobei natürlich der Einsatz automatischer Steuerungsmittel naheliegt. Gleiches gilt auch für die Grundeinstellung der Vorspannung der Druckfeder(n) 27.The invention is of course not limited to the exemplary embodiments shown in the figures and laid down in the description. It goes without saying that numerous constructive modifications are within the scope of the invention. So it is conceivable to transfer the drive suspension to pallet trucks or other types of conveyors, for example to those in which the operator is traveling on the vehicle. It is also possible within the scope of the specialist to lift cylinder 45 in the longitudinal axis to design the lift truck to be longitudinally displaceable and lockable by known mechanical, electrical, hydraulic or pneumatic means, in order thereby to preselectably change the lever ratio and thus the ground contact pressure of the drive wheel 5 according to the given operating conditions, the use of automatic control means, of course, being obvious. The same applies to the basic setting of the preload of the compression spring (s) 27.

TeilelisteParts list

  • 1 Antriebsrahmen1 drive frame
  • 2 Lastrahmen2 load frames
  • 3 Antriebseinheit3 drive unit
  • 4 Fahrdeichsel4 drawbar
  • 5 Antriebsrad5 drive wheel
  • 6 Schwenkrolle6 swivel castor
  • 7 Lagersteg7 landing stage
  • 8 Energieversorgungseinheit8 power supply unit
  • 9 Lastarm9 load arm
  • 10 Lastrolle10 load roller
  • 11 Radgabel11 wheel fork
  • 12 Zug- oder Druckgestänge12 pull or push rods
  • 13 Getriebe13 gears
  • 14 Drehkranzlager14 slewing ring bearings
  • 15 Fahrmotor15 traction motor
  • 16 Befestigungsplatte16 mounting plate
  • 17 Lageraußenring17 bearing outer ring
  • 18 Getriebeplatte18 gear plate
  • 19 Bohrung19 hole
  • 20 unterer Motorflansch20 lower motor flange
  • 21 Lagerinnenring21 bearing inner ring
  • 22 Bohrung22 hole
  • 23 Spannplatte23 clamping plate
  • 24 Bohrung24 hole
  • 25 Spannbolzen25 clamping bolts
  • 26 Federteller26 spring washers
  • 27 Federmittel (Druckfeder)27 spring means (compression spring)
  • 28 Spannmutter28 clamping nut
  • 29 Fahrbahnoberfläche29 road surface
  • 30 oberer Motorflansch30 upper motor flange
  • 31 Motorbremse31 Engine brake
  • 32 Deichselflansch32 drawbar flange
  • 33 Distanzbüchse33 spacer sleeve
  • 34 Deichselaufbau34 Drawbar structure
  • 35 Deichsellager35 drawbar bearings
  • 36 Schwinghebel36 rocker arms
  • 37 langer Hebelschenkel37 long lever arm
  • 38 Winkelhebel38 angle lever
  • 39 Gehäuseausladung39 Housing projection
  • 40 Längsachse des Hubwagens40 Longitudinal axis of the pallet truck
  • 41 oberer Querhebel41 upper cross lever
  • 42 unterer Querhebel42 lower cross lever
  • 43 Lagerlaschen43 bearing plates
  • 44 Längshebel44 longitudinal lever
  • 45 Hubzylinder45 lifting cylinders
  • 46 Lagerpunkt46 bearing point
  • 47 langer Hebelarm47 long lever arm
  • 48 kurzer Hebelarm48 short lever arm
  • 49 Stütz- und Führungsplatte49 Support and guide plate
  • 50 Hubkolben50 reciprocating pistons
  • 51 Lagerbohrung51 bearing bore
  • 52 Freilauf52 freewheel
  • 53 Hubmast53 mast
  • 54 Radgabelpaar54 pair of wheel forks
  • 55 Hubschlitten55 lifting slides
  • 56 Lasttragemittel (Lastgabel)56 load carrying means (load fork)
  • 57 kurzer Hebelschenkel57 short lever arm

Claims (12)

1. Hubwagen, vorzugsweise deichselgesteuerter Gehhubwagen, mit einer in vertikaler Richtung federbelastet vorgespannten Antriebseinheit, die mittels einer Hebelparallelogramm-­Aufhängung an einem nicht anhebbaren Rahmenteil des Hubwagens höhenausgleichbar angelenkt und deren Bodenkontaktdruck lastkraftabhängig variierbar ist und mit zumindest einem Hubyzlinder für den Niederhub (Basishub) eines anhebbaren Rahmenteils,
dadurch gekennzeichnet,
daß der Hubzylinder (45) sich unter Ausnutzung seiner Hubkraft gegensinnig abstützend direkt zwischen dem anhebbaren Rahmenteil (49) des Hubwagens und der Hebelparallelogramm-Aufhängung (41, 42, 44) angeordnet ist.1. Pallet truck, preferably a drawbar-controlled pedestrian pallet truck, with a drive unit that is spring-loaded in the vertical direction, which is articulated in a height-adjustable manner by means of a lever parallelogram suspension on a frame part of the pallet truck that cannot be raised and whose ground contact pressure can be varied depending on the load force and with at least one lifting cylinder for the low lift (base stroke) lifting frame part,
characterized,
that the lifting cylinder (45), utilizing its lifting force in opposite directions, is arranged directly between the lifting frame part (49) of the lifting truck and the lever parallelogram suspension (41, 42, 44). 2. Hubwagen nach Anspruch 1,
dadurch gekennzeichnet,
daß zur Abstutzung des Hubzylinders (45) in Hubrichtung das anhebbare Rahmenteil als lastrahmenfixierte Stütz- und Führungs­platte (49) für einen Hubkolben (50) des Hubzylinders (45) ausgebildet ist.2. Pallet truck according to claim 1,
characterized,
that to support the lifting cylinder (45) in the lifting direction, the liftable frame part is designed as a load frame fixed support and guide plate (49) for a lifting piston (50) of the lifting cylinder (45). 3. Hubwagen nach Anspruch 1 und/oder 2,
dadurch gekennzeichnet,
daß der Hubzylinder (45) zur Abstutzung in Senkrichtung in einem bestimmten Hebelverhältnis (47 : 48) in der Hebel­parallelogramm-Aufhängung (41, 42, 44) drehbar gelagert und zumindest ein Teil seiner Abstützkraft über einen (47) von zwei durch den Lagerpunkt (46) gebildeten Hebelarme (47, 48) auf die Antriebseinheit (3) übertragbar ist.3. Pallet truck according to claim 1 and / or 2,
characterized,
that the lifting cylinder (45) is rotatably supported in the lever parallelogram suspension (41, 42, 44) in the lever parallelogram suspension (41, 42, 44) for support in the lowering direction and at least part of its supporting force is via one (47) of two through the bearing point ( 46) formed lever arms (47, 48) can be transferred to the drive unit (3). 4. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß die Abstützkraft des Hubzylinders (45) beladungsabhängig zur Vergrößerung des Bodenkontaktdruckes eines Antriebsrades (5) der Antriebseinheit (3) vorgesehen ist.4. Pallet truck according to one or more of the preceding claims,
characterized,
that the supporting force of the lifting cylinder (45) is provided depending on the load to increase the ground contact pressure of a drive wheel (5) of the drive unit (3). 5. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß die Hebelparallelogramm-Aufhängung (41, 42, 44) aus zwei schwenkbaren Querhebeln (41, 42) gebildet wird, die parallel in wählbarem Abstand zueinander an ihrem einen Ende in dem nicht anhebbaren Rahmenteil (1) und an ihrem anderen Ende in einem antriebsfixierten Längshebel (44) drehbar gelagert sind.5. Pallet truck according to one or more of the preceding claims,
characterized,
that the lever parallelogram suspension (41, 42, 44) is formed from two pivotable transverse levers (41, 42) which are parallel to each other at a selectable distance at one end in the non-lifting frame part (1) and at the other end in a drive-fixed Longitudinal lever (44) are rotatably mounted. 6. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß die beiden Querhebel (41, 42) horizontal und der Längshebel (44) vertikal angeordnet sind und der Hubzylinder (45) im unteren Querhebel (42) gelagert ist.6. Pallet truck according to one or more of the preceding claims,
characterized,
that the two transverse levers (41, 42) are arranged horizontally and the longitudinal lever (44) vertically and the lifting cylinder (45) is mounted in the lower transverse lever (42). 7. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß der auf die Antriebseinheit drückende Hebelarm (47) länger ist, als der andere Hebelarm (48).7. Pallet truck according to one or more of the preceding claims,
characterized,
that the lever arm (47) pressing on the drive unit is longer than the other lever arm (48). 8. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß der Hubzylinder (45) mit einem Freilauf (52) versehen ist, der bei abgesenktem Hubwagen ein Auslenken der Antriebseinheit (3) vertikal nach unten ermöglicht.8. Pallet truck according to one or more of the preceding claims,
characterized,
that the lifting cylinder (45) is provided with a freewheel (52) which allows the drive unit (3) to be deflected vertically downward when the lifting truck is lowered. 9. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß der Freilauf (52) als zwischen der Oberseite der Stütz- und Führungsplatte (49) und dem oberen Ende des Hubkolbens (50) des Hubzylinders (45) vorgesehener Resthub ausgebildet ist.9. Pallet truck according to one or more of the preceding claims,
characterized,
that the freewheel (52) is designed as a residual stroke provided between the upper side of the support and guide plate (49) and the upper end of the lifting piston (50) of the lifting cylinder (45). 10. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß der Hubzylinder (45) zwecks vorwählbarer Veränderung des Hebelverhältnisses (47 : 48) am Querhebel (42) der Parallelogramm-Aufhängung (41, 42, 44) in Längsrichtung des Hubwagens manuell und/oder automatisch verschiebbar und arretierbar ist.10. Pallet truck according to one or more of the preceding claims,
characterized,
that the lifting cylinder (45) for the preselectable change of the lever ratio (47: 48) on the transverse lever (42) of the parallelogram suspension (41, 42, 44) in the longitudinal direction of the lifting truck is manually and / or automatically displaceable and lockable. 11. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß zur federbelasteten Vorspannung der Antriebseinheit (3) zwischen dem nicht anhebbaren Rahmenteil (1) und einem antriebsfesten Bauteil (18) zumindest eine Druckfeder (27) angeordnet ist.11. Pallet truck according to one or more of the preceding claims,
characterized,
that at least one compression spring (27) is arranged for the spring-loaded pretensioning of the drive unit (3) between the frame part (1) which cannot be raised and a component (18) fixed to the drive. 12. Hubwagen nach einem oder mehreren der vorangehenden Ansprüche,
dadurch gekennzeichnet,
daß die Vorspannung der Druckfeder (17), vorzugsweise mittels einer Spannmutter (28), beliebig einstellbar ist.12. Pallet truck according to one or more of the preceding claims,
characterized,
that the bias of the compression spring (17), preferably by means of a clamping nut (28), can be adjusted as desired.
EP90102780A 1989-02-17 1990-02-13 Lift-truck with a vertically spring-preloaded drive unit Expired - Lifetime EP0383254B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT90102780T ATE95127T1 (en) 1989-02-17 1990-02-13 PALLET TRUCK WITH A VERTICALLY SPRING LOADED PRELOADED DRIVE UNIT.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3904798A DE3904798A1 (en) 1989-02-17 1989-02-17 LIFTING WAGON WITH A DRIVE UNIT PRELOADLY PRESSED IN A VERTICAL DIRECTION
DE3904798 1989-02-17

Publications (3)

Publication Number Publication Date
EP0383254A2 true EP0383254A2 (en) 1990-08-22
EP0383254A3 EP0383254A3 (en) 1991-03-06
EP0383254B1 EP0383254B1 (en) 1993-09-29

Family

ID=6374297

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90102780A Expired - Lifetime EP0383254B1 (en) 1989-02-17 1990-02-13 Lift-truck with a vertically spring-preloaded drive unit

Country Status (5)

Country Link
US (1) US5113960A (en)
EP (1) EP0383254B1 (en)
AT (1) ATE95127T1 (en)
DE (2) DE3904798A1 (en)
ES (1) ES2046550T3 (en)

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EP1897842A2 (en) * 2006-09-06 2008-03-12 Jungheinrich Aktiengesellschaft Premounting unit for operating an industrial truck
WO2015055306A1 (en) * 2013-10-15 2015-04-23 Eisenmann Se Conveyor unit and conveyor system for conveying load carriers
EP2910513A1 (en) * 2014-02-21 2015-08-26 Mobilev Cranes Lifting apparatus with a height regulating device
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Also Published As

Publication number Publication date
DE3904798A1 (en) 1990-08-30
ATE95127T1 (en) 1993-10-15
DE59002871D1 (en) 1993-11-04
US5113960A (en) 1992-05-19
EP0383254B1 (en) 1993-09-29
EP0383254A3 (en) 1991-03-06
ES2046550T3 (en) 1994-02-01
DE3904798C2 (en) 1992-01-23

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